A conventional linear motor type elevator includes a car arranged to be able move vertically in a hoistway and a counterweight for balancing the car. The car is moved vertically by a linear motor installed in the hoistway. The linear motor includes a moving element and a stator, and motion of the car is the result of relative motion between the moving element and the stator. Typically, the moving element is integral to the counterweight and includes a through-hole. A column-shaped stator extends through the through-hole. One end of a rope is fixed to the moving element, and the other end is attached to the car via a sheave. If a drive current is supplied to the linear motor, a magnetic force is generated between the stator and the moving element, and the moving element moves vertically with respect to the stator. As a result, the car is moved vertically.
In this conventional linear motor type elevator, only the upper and lower ends of the column-shaped stator are fixed and supported on the building. The middle portion is not supported at all to avoid interference with the moving element. This configuration permits a relationship in which the moving element moves along the extent of the stator. For this reason, the length of the stator has a limited length of about thirty meters. As a result of this limitation, the conventional linear motor cannot be used as a drive source in an elevator for a building requiring longer runs.
Another consideration with linear motor elevators is the output of the linear motor required to drive the elevator. It is desirable to minimize the output required to drive the elevator, thereby minimizing the size, weight and cost of the linear motor elevator.